ZBrushCentral

Uneven symmetry strength

Hi. I am using zbrush r6 and am using symmetry on sculpting a head. The symmetry positioning works fine, however the brush strength is less strong on the side that I do not directly sculpt on. It does not matter which side I directly sculpt on, the other side is always less strong. The model was begun in zbrush (using a sphere) and never has been exported. I am only using the basic brushes such as move, clay buildup and standard. What might be causing this? How would I fix it?

Thanks in advance

First off, why are you using 4R6 instead of the free upgrade to ZBrush 2018?